1. Field of the Invention
The present invention relates to an access right management system which manages an access right for a document.
2. Description of the Prior Art
In recent years, access right management servers have been developed in which access rights (browsing right, editing right, printing right, or the like) for documents are set in order to prevent information leakage from the documents. In the server, a validity period can also be set for the document. When the validity period expires, any access right set previously is invalidated.
A policy server is known as one access right management server for a document. The policy server issues a policy for a portable document format (PDF) file which is one type of a document and sets the access right and the validity period by applying the policy to the document.
In the related art, there is a technique of achieving a more strong/powerful management of access right for a document by operating the access right management server in combination with a document management server.
According to Japanese Patent Laid-Open No. 2007-058567, in the case where a document managed by the document management server is delivered through e-mail or the like, the access right management server sets an access right for the document corresponding to an access right for the document management server. Delivering the document to be delivered after the access right has been applied thereto prevents information leakage from the document even if the document is delivered to an unintended user.
According to Japanese Patent Laid-Open No. 2007-200140, an access right management server limits not only an access right for a document but also the number of times of operation on the document for which the access right is set, and updates the access right when the number of times of operation reaches the limited number of times.
However, the techniques of the related art are insufficient in controlling an access right of a document managed by a document management server when the same document exists in another device outside the management of the document management server.